1. Field of the Invention
This invention relates generally to a signal gating system, and more particularly to a signal control system to be applied to a cyclic signal such as a video signal. A dot-like noise cancelling circuit installed in a television color camera system is one of applications of this invention as described herein.
2. Description of the Prior Art
There has been known a color camera system wherein a vertical correlation between two successive line video signals is introduced upon separating a modulated color signal and a luminance signal from output signals derived from an imaging device having a color coding filter. In this separation system, the video signals have to have the vertical correlation. However, there is such a case that the vertical correlation is feeble or no vertical correlation exists. In case of feeble vertical correlation, two information signals cannot be separated completely. That is, in one signal component there remains the other signal component in multi-imposed state, and this residual signal component affects and on a reproduce picture badly. In other words, a dot-like undesirable pattern appears on the reproduced picture screen.